The present invention relates to a fluid reservoir for a multi-circuit hydraulic brake system, in particular for automotive vehicles, which comprises two reservoir housing sections including a lower section with ports for connecting to a master brake cylinder and an upper section with a filler hole and two electric fluid level warning devices communicating with two contact chambers in the housing, both housing sections being subdivided into two separate compartments by a partition wall including openings, with each of the compartments lying vertically below an associated one of the two contact chambers and having an associated one of the ports opening therein. A fluid reservoir of this type is known from German Patent DE-OS No. 2,855,171.
In the fluid reservoir known from German Patent DE-OS No. 2,855,171, the partition wall separating the two compartments extends below the filler hole vertically to the connecting line between the two ports connected to a master brake cylinder. When the reservoir is to be filled with brake fluid, this arrangement does not allow a sufficiently deep introduction of the filling device into the reservoir filler neck so that a perfect and safe guiding of the filling device in the filler hole is not ensured.
With the known subdivision of the fluid reservoir compartments, the two fluid level warning devices are arranged one behind the other relative to the connecting line between the two ports. The disadvantage of this arrangement is that in the event of an inclined position in the direction of the connecting line between the ports of the fluid reservoir, the two floats may show a substantial difference in level because of the resulting brake fluid level, so that a false alarm may be released by the fluid at the lower level.
If floats with relatively large diameters are to be arranged in the compartments of the fluid reservoir while at the same time one of the two compartments is to have the smallest possible volume, this is hardly realizable in the known fluid reservoir in which the compartments are arranged in series relative to the connecting line between the ports, because the float associated with each compartment is required to be at a sufficiently large distance from the walls bounding the associated compartment in order to ensure free movability of the float in this particular compartment. The result is an overdimensioned compartment so that part of the brake fluid in this compartment is not utilized, resulting in increased material cost.